Presentation on theme: "Database Planning, Design, and Administration. Objectives Main components of an information system. Main stages of database system development lifecycle."— Presentation transcript:
Database Planning, Design, and Administration
Objectives Main components of an information system. Main stages of database system development lifecycle. Main phases of database design: conceptual, logical, and physical design.
Objectives How to evaluate and select a DBMS. Distinction between data administration and database administration. Purpose and tasks associated with data administration and database administration.
Software Depression Last few decades have seen proliferation of software applications, many requiring constant maintenance involving: correcting faults, implementing new user requirements, modifying software to run on new or upgraded platforms. Effort spent on maintenance began to absorb resources at an alarming rate.
Software Depression As a result, many major software projects were late, over budget, unreliable, difficult to maintain, performed poorly. In late 1960s, led to ‘software crisis’, now refer to as the ‘software depression’.
Software Depression Major reasons for failure of software projects includes: lack of a complete requirements specification; lack of appropriate development methodology; poor decomposition of design into manageable components. Structured approach to development was proposed called Information Systems Lifecycle (ISLC).
Information System Resources that enable collection, management, control, and dissemination of information throughout an organization. Database is fundamental component of IS, and its development/usage should be viewed from perspective of the wider requirements of the organization.
Database System Development Lifecycle Database planning System definition Requirements collection and analysis Database design DBMS selection (optional)
Database System Development Lifecycle Application design Prototyping (optional) Implementation Data conversion and loading Testing Operational maintenance
Stages of the Database System Development Lifecycle
Database Planning Management activities that allow stages of database system development lifecycle to be realized as efficiently and effectively as possible. Must be integrated with overall IS strategy of the organization.
Database Planning – Mission Statement Mission statement for the database project defines major aims of database application. Those driving database project normally define the mission statement. Mission statement helps clarify purpose of the database project and provides clearer path towards the efficient and effective creation of required database system.
Database Planning – Mission Objectives Once mission statement is defined, mission objectives are defined. Each objective should identify a particular task that the database must support. May be accompanied by some additional information that specifies the work to be done, the resources with which to do it, and the money to pay for it all.
Database Planning Database planning should also include development of standards that govern: how data will be collected, how the format should be specified, what necessary documentation will be needed, how design and implementation should proceed.
System Definition Describes scope and boundaries of database system and the major user views. User view defines what is required of a database system from perspective of: a particular job role (such as Manager or Supervisor) or enterprise application area (such as marketing, personnel, or stock control).
System Definition Database application may have one or more user views. Identifying user views helps ensure that no major users of the database are forgotten when developing requirements for new system. User views also help in development of complex database system allowing requirements to be broken down into manageable pieces.